Leon lcb11211@swbelldotnet writes:
On 8/29/2018 12:40 PM, dpb wrote:
On 8/29/2018 10:58 AM, Leon wrote:
...

In the single bag situation the bag acts as the filter and the
collector.Â* With the two bag units the lower bag catches the bulk and
normally does not let air penetrate.Â* It is normally a plastic bag.
The upper bag is strictly the filter/air outlet.Â* Oddly the cloth
upper bags tend to filter better once they get a coating of dust
covering the inside surface.
...

Unless you upgrade or buy upper/top-end unit, run-of-the-mill DC filter
bags are typically 5, 10 or even 30(!) micron so fines are pretty easy
to get by.Â* What _is_ trapped simply blocks some of the open pore area
effectively making it a better filter (with reduced air flow, of course).

--

Absolutely! And even the better pleated units become caked inside, but
fortunately you can spin the brush inside and increase the efficiency
when suction drops.


Or you can just smack the upper bag a couple of times.